<?php
/**
 * CUniqueValidator class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CUniqueValidator validates that the attribute value is unique in the corresponding database table.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CUniqueValidator.php 3260 2011-06-13 20:56:54Z alexander.makarow $
 * @package system.validators
 * @since 1.0
 */
class CUniqueValidator extends CValidator
{
    /**
     * @var boolean whether the comparison is case sensitive. Defaults to true.
     * Note, by setting it to false, you are assuming the attribute type is string.
     */
    public $caseSensitive=true;
    /**
     * @var boolean whether the attribute value can be null or empty. Defaults to true,
     * meaning that if the attribute is empty, it is considered valid.
     */
    public $allowEmpty=true;
    /**
     * @var string the ActiveRecord class name that should be used to
     * look for the attribute value being validated. Defaults to null, meaning using
     * the class of the object currently being validated.
     * You may use path alias to reference a class name here.
     * @see attributeName
     * @since 1.0.8
     */
    public $className;
    /**
     * @var string the ActiveRecord class attribute name that should be
     * used to look for the attribute value being validated. Defaults to null,
     * meaning using the name of the attribute being validated.
     * @see className
     * @since 1.0.8
     */
    public $attributeName;
    /**
     * @var array additional query criteria. This will be combined with the condition
     * that checks if the attribute value exists in the corresponding table column.
     * This array will be used to instantiate a {@link CDbCriteria} object.
     * @since 1.0.8
     */
    public $criteria=array();
    /**
     * @var string the user-defined error message. The placeholders "{attribute}" and "{value}"
     * are recognized, which will be replaced with the actual attribute name and value, respectively.
     */
    public $message;
    /**
     * @var boolean whether this validation rule should be skipped if when there is already a validation
     * error for the current attribute. Defaults to true.
     * @since 1.1.1
     */
    public $skipOnError=true;


    /**
     * Validates the attribute of the object.
     * If there is any error, the error message is added to the object.
     * @param CModel $object the object being validated
     * @param string $attribute the attribute being validated
     */
    protected function validateAttribute($object,$attribute)
    {
        $value=$object->$attribute;
        if($this->allowEmpty && $this->isEmpty($value))
        return;

        $className=$this->className===null?get_class($object):Yii::import($this->className);
        $attributeName=$this->attributeName===null?$attribute:$this->attributeName;
        $finder=CActiveRecord::model($className);
        $table=$finder->getTableSchema();
        if(($column=$table->getColumn($attributeName))===null)
        throw new CException(Yii::t('yii','Table "{table}" does not have a column named "{column}".',
        array('{column}'=>$attributeName,'{table}'=>$table->name)));

        $columnName=$column->rawName;
        $criteria=new CDbCriteria(array(
			'condition'=>$this->caseSensitive ? "$columnName=:value" : "LOWER($columnName)=LOWER(:value)",
			'params'=>array(':value'=>$value),
        ));
        if($this->criteria!==array())
        $criteria->mergeWith($this->criteria);

        if(!$object instanceof CActiveRecord || $object->isNewRecord || $object->tableName()!==$finder->tableName())
        $exists=$finder->exists($criteria);
        else
        {
            $criteria->limit=2;
            $objects=$finder->findAll($criteria);
            $n=count($objects);
            if($n===1)
            {
                if($column->isPrimaryKey)  // primary key is modified and not unique
                $exists=$object->getOldPrimaryKey()!=$object->getPrimaryKey();
                else
                {
                    // non-primary key, need to exclude the current record based on PK
                    $exists=array_shift($objects)->getPrimaryKey()!=$object->getOldPrimaryKey();
                }
            }
            else
            $exists=$n>1;
        }

        if($exists)
        {
            $message=$this->message!==null?$this->message:Yii::t('yii','{attribute} "{value}" has already been taken.');
            $this->addError($object,$attribute,$message,array('{value}'=>$value));
        }
    }
}

